Inflammatory Bowel Disease (IBD) is a group of inflammatory conditions that affect colon and small intestine. The major types of IBD are Crohn's disease (CD) and ulcerative colitis (UC). IBD pathogenesis is characterized by different angiogenic regulation contributing to and perpetuating a chronic inflammatory state in the bowel (Chidlow et al., 2006, Am J Physiol. Gastrointest. Liver Physiol., 29, G5-G18). Crohn's disease can affect any part of the gastrointestinal tract, whereas ulcerative colitis is typically restricted to the colon and rectum (Summers R W, Elliott D E, Qadir K, Urban J F, Thompson R, Weinstock J V (2003) Am. J. Gastroentol., 98:2034-2041). Depending on its severity, treatment of ulcerative colitis may require immunosuppression to control its symptoms and treatment usually involves the administration of anti-inflammatory molecules.
IBD is known to be characterized by upregulation of pro-inflammatory cytokines, such as IFN-γ, IL-6 and IL-12 (e.g. IL-12p70). For example, Crohn's disease is known to be associated with excess IL-12/IL-23 and IFN-γ/IL-17 production (Strober et al. (2007), The Journal of Clinical Investigation, 117(3), 514-521). Synthesis of IL-12p70 and IL-23 during active Crohn's disease has also been reported (Fuss et al. 2006, Inflamm. Bowel Dis. 12:9-15).
Fibronectin (FN) is a glycoprotein and is widely expressed in a variety of normal tissues and body fluids. It is a component of the extracellular matrix (ECM), and plays a role in many biological processes, including cellular adhesion, cellular migration, haemostasis, thrombosis, wound healing, tissue differentiation and oncogenic transformation.
Different FN isoforms are generated by alternative splicing of three regions (ED-A, ED-B, IIICS) of the primary transcript FN pre-mRNA, a process that is modulated by cytokines and extracellular pH (Balza (1988) FEBS Lett., 228, 42-44; Carnemolla (1989) J. Cell Biol., 106, 1139-1148; Borsi (1990) FEBS Lett. 261, 175-178). Fibronectin contains two type-III globular extra-domains which may undergo alternative splicing: ED-A and ED-B (ffrench-Constant (1995) Exp. Cell Res., 22, 261-271, Kaspar et al. (2006) Int. J. cancer, 118, 1331-1339). The ED-As of mouse fibronectin and human fibronectin are 96.7% identical (only 3 amino acids differ between the two 90 amino acid sequences).
Expression of the ED-A of fibronectin has been reported in tumour cells and in solid tumours at the mRNA level in breast cancer (Jacobs et al. (2002) Human Pathol, 33, 29-38, Matsumoto et al. (1999) Jpn. J. Cancer Res., 90, 320-325) and liver cancer (Oyama et al. (1989) JBC, 264, 10331-10334, Tavian et al. (1994) Int. J. Cancer, 56, 820-825) and at the level of isolated protein in fibrosarcoma, rhabdomyosarcoma and melanoma (Borsi et al. (1987) J. Cell Biol., 104, 595-560). Other than cancer, expression of the ED-A of fibronectin has been reported in rheumatoid arthritis (WO2009/056268). WO2010/078950 also reports expression of ED-A of fibronectin in endometriosis, psoriasis and psoriatic arthritis, however histochemical analysis revealed a very weak to virtually absent expression of ED-A in multiple sclerosis and in ulcerative colitis. Immunohistochemical analyses reported by Brenmoehl et al. (Int. J. Colorectal Dis. (2007) 22:611-623) show that ED-A expression is decreased in inflamed intestinal mucosa of CD patients when compared to control mucosa and increased in ulcerative colitis. Brenmoehl et al. (2007) also report increased expression of ED-A and ED-B isoforms in fibrotic mucosa of CD patients. Expression of ED-A and ED-B isoforms in fibrotic mucosa is expected as these fibronectin isoforms are known to be involved in wound healing. There is no suggestion in Brenmoehl et al. (2007) that ED-A is expressed during (active) CD, given the decreased expression of ED-A in inflamed intestinal mucosa of CD patients compared with mucosa derived from control patients. The use binding members which bind the ED-A isoform of fibronectin for the treatment or diagnosis of IBD is also not disclosed in this document.
Interleukin-10 (IL-10) is an anti-inflammatory cytokine that functions as an important regulator of the immune system. Although IL-10 is known to have many different roles in the immune system, its two major activities include inhibition of cytokine production by macrophages and inhibition of the accessory functions of macrophages during T cell activation (Abbas A, Lichtman A, Pober J., 1994, Cellular and Molecular Immunology. 2nd Ed. Philadelphia: W.B. Saunders Company). The effects of these actions cause IL-10 to play mainly an anti-inflammatory role in the immune system. IL-10 was originally known as the cytokine synthesis inhibiting factor (CSIF), and the discovery of this protein was based on its biological activity (Delves P, Roitt I (eds), 1998, Encyclopedia of Immunology, 2nd Ed. San Diego: Academic Press). Because of its well known anti-inflammatory properties, IL-10 therapy was introduced as a potential new anti-inflammatory therapy in Crohn's disease (CD) (Fedorak et al., Gastroenterology (2000) 119, 1473-1482; Schreiber et al., Gastroenterology (2000) 119, 1461-1472; Colombel et al., Gut (2001) 49, 42-46).
Asadullah et al. (Pharmacology Reviews, (2003), 55, 245-269) review the state of the art of Interleukin-10 therapy in a number of inflammatory diseases. When reviewing chronic inflammatory bowel disease, Asadullah et al. report that several large multicenter trials were performed, testing multiple IL-10 dosages in patients with mild/moderate or therapy refractory CD, as well as in patients undergoing curative ileal or ileocolonic resection to prevent endoscopic postoperative occurrence by systemic administration (Fedorak et al., Gastroenterology (2000) 119, 1473-1482; Schreiber et al., Gastroenterology (2000) 119, 1461-1472; Colombel et al., Gut (2001) 49, 42-46). The data indicate that IL-10 therapy is safe and well tolerated. However, IL-10 treatment did not result in significantly higher remission rates or clinical improvement compared with placebo treatment.
Overall the clinical results were found to be unsatisfying and several explanations for the disappointment with this therapeutic strategy were discussed by Herfarth and Scholmerich (Gut (2002) 50, 146-147).
Therefore, there is a need for effective treatments of various IBD states.